Web-tensioning device



Nov. 4, 1941. R. A. STEWART WEB-TENSIONING DEVICE Filed Feb. 8, 1939 3Sheets-Sheet l INVENTOR ROY A. STEWART ATTOf N Nov. 4, 1941. R. A.STEWART WEB-TENSIONING DEVICE Filed Feb. 8, 1959 3 ShaetS-Sheet 2 oINVENTOR ROY A. STEWART Nov. 4, 1941. R. A. STEWART 2,251,391

WEB-TENSIONING DEVICE Filed Feb. 8, 1939 3 Sheets-Sheet S INVENTOR ROYA. STEWART ATTOR Patented Nov. 4, 1941 UNITED STATES PATENT OFFICEWEB-TENSIONING DEVICE Roy A. Stewart, Decatur, 111-.

Application February 8, 1939, Serial No. 255,261

Claims.

This invention relates to web supply apparatus and in particular toapparatus to control the unwinding of a plurality of web rolls such asmay b used to feed one or more webs to a multideck or unit rotaryprinting press.

It is desirable in feeding web to a printing machine that there be atension produced in the web to facilitate good printing and this tensionmay be providedby braking the web roll. By controlling this braking ofthe web roll according to the tension in the web many advantages areobtained which include uniform web tension during unwinding of the webroll and the prevention of overrunning of the web roll should the webbreak or the feeding of the web roll stop suddenly. With the use of highspeed printing machines it becomes increasingly desirable to be able tofeed a web under substantially uniform tension during the life of thesupplying web roll, without manual adjustment, or during an entireprinting run, so that once the printing machine is started it need notbe stopped, barring breakdown, until the printing to be done iscompleted.

It is an object of the present invention to provide web tensionapparatus such that one or more webs may be continuously andsuccessively fed from a plurality of web rolls as they expire, each ofthe continuous webs being controlled by the same web tension controlmechanism throughout.

A further object is to provide web control apparatus whereby a pluralityof web rolls may be controlled by the tension in one web.

Another object is to provide apparatus of the type mentioned which issimple in design and construction and inexpensive to manufacture, andwhich may be operated with a minimum of supervision.

Other objects and advantages will become apparent from the followingdetailed description at:- companied by the drawings, in which:

Figure 1 is a diagrammatic view of a system of web rolls from which maybe fed a plurality of webs, illustrating a supply system embodying thepresent invention;

Fig. 2 is a side elevation showing the control system for controllingthe tension in a web and the unwinding of the web roll;

Fig. 3 is an enlarged sectional view taken substantially on line 3-3 ofFig. 2;

Fig. 4 is an enlarged sectional view taken substantially on line 4-4 ofFig. 2;

Fig. 5 is an end elevational view taken substantially on the line 5-5 ofFig. 2, showing construction details of the control mechanism; and

Fig. 6 is a side elevational view'showing further construction detailsof control mechanism.

In brief, one practical application of web supply apparatus embodyingthe present invention comprises a tension responsive device associatedwith the web to maintain substantially uniform tension by transmittingchanges in web tension to suitable braking means on the web roll and byapplying or releasing the braking means to correct the change in webtension. It has been found that one very desirable way of doing this isto have the tension responsive device connected with a primary hydraulicfluid brake cylinder which may b selectively connected to a plurality ofsecondary hydraulic fluid brake cylinders adapted to operate the brakingmeans. In the embodiment of the invention shown herein the tensionresponsive device creates amechanical force suitable to correct thebraking means and this'mechanical force is converted by the primarybrake cylinder to hydraulic fluid pressure which may be transmitted tothe secondary brake cylinder, reconverted into a mechanical force andused to apply or release the braking means. The use of a hydraulic fluidsystem is very advantageous because the transmittal of force to any of aplurality of varied locations is greatly facilitated.

With reference to the accompanying drawings, in which like partsthroughout the several views are indicated by the same referencenumerals, a system of web supply apparatus is shown diagrammatically inFig. 1. A plurality of web rolls are shown arranged in four decks sothat, if desired, from one to four webs may be fed simultaneously to aprinting machine, such as, for example, a multi-deck or unit rotaryprinting press. Deck I contains web rolls R1 and R2 and a web W1 is fedfrom this deck. The parts of mechanisms located in this deck will bedenoted by numerals below 100. Deck II contains web rolls R3 and R4,feeds a web W200 and the parts situated in this deck will be denoted bynumerals in the two hundreds. In a similar manner, decks III and IVcontain web rolls R5, R6 and R7, R8 respectively, and feed webs W300 andW400 respectively. Parts situated in decks III and IV will be denoted bynumerals in the three hundreds and four hundreds, respectively. Thisgrouping into decks and numbering the parts according to decks has beenarbitrarily chosen for the sake of brevity and clarity of description.Since the mechanism in each deck is substantially similar, only that indeck I will be fully described.

Web rolls R1 and R2 may be carried by'suitable web roll shafts I mountedfor rotation in a suitable frame or roll stand 2. The brake mechanismfor the web rolls is shown in Figs. 2, 3 and 4 and comprises the brakebands 3 carried by arcuate brake shoes 4 and 5 which are pivotallyconnected at one end about a pivot 6. The opposite or free end of theshoe 5 terminates in an upstanding lug l which is apertured to receivean eye bolt 8 which is inserted so that the enlarged portion I0 of theeye bolt remains on the outside of the shoe. The shaft portion H of theeye bolt passes through an aperture in the upstanding lug |2 on the freeend of the brake shoe 4 where its threaded portion may carry a handwheel |3. Pivoted at the eye portion III of the eye bolt 8 is a bellcrank lever I4.

This lever has a free long arm |5 which'is bifurcated to provide a pairof short arms I6 pivoted to the brake shoe 5 by a pivot which passesthrough the arms l6 and also through boss integral with the brake shoe.The brake mechanism may be operated to effect braking of the web roll byexerting force on the arm |5 of the lever |4 so that the arms l6 of thelever l4 force the shoe 5 toward the shoe 4 to create an increasedpressure of the band 3 against a drum |8 carried by the web roll shaftFurther, the brake may also be operated by turning the hand wheel |3when the lever arm 45 is held so that the shoes are drawn one toward theother by the action of the bolt 8, the enlarged portion of which servesto support the lug 1 of the shoe 5, while the hand wheel .advances thelug l2 of the shoe 4.

A web W1, fed from deck I, is led upwardly over a guide roller around aguide roller 2| back around a guide roller 22, then forward again over aguide roller 23, from which it passes to the rolls or printing cylindersof the printing machine (not shown). The guide roller 23 is journaled inthe side frame 2 while the guide rollers 20, 2| and 22 are carried'by .apair of spaced brackets 24 secured to the frame 2. Of course, one ormore of the guide rollers may be mounted, as, is well known in the art,so as to l be spring pressed against the web to cushion the web fromshocks which would tend to break ,or tear the web. Between guide rollers22 and 23 the web is passed under a movable or floating control roller25 carried by the ends of arms 26 which are pivotally mounted on a shaft29 which is supported in the brackets 24 and around which the guideroller 20 freely rotates. At one side of the frame 2 a lever arm 21 isprovided and it is pivotally mounted on the end of the shaft 29 andsecured so as to move with the arms 26 (see Figs. 5 and 6). One end ofthe lever 21 carries a weight 28 which may be adjustably positioned atvarious distances from the pivot point. The other end of the lever arm21, located on the opposite side of the pivot point, is pivotallyconnected to a piston rod 30 of a dash pot 3| which is pivotallyanchored to the frame 2 at 32.

The weight 28 tends to rotate the arms 26 in a counterclockwisedirection (looking at Fig. 6) so as to draw the web into a loop betweenthe rollers 22 and 23 to substantially the positions shown in dottedline. The weight 28 is made adjustable along the lever 21 so that it maybe positioned to induce the various desired tensions to be maintained inthe web. The dash pot 3| is provided so that upon an emergency stoppingof the web feed or a sudden braking of the web the,

movement of the arms 26 from the solid line position to the dotted lineposition shown in Fig.

6 may be effected in a gradual manner. Movement of the arms 26 produceseither an increase or a decrease in the braking pressure of the brakeshoes against the drum and the web roll,

Means for transmitting the mechanical movement of the arms 26 to theprimary brake cylinder for conversion into fluid pressure are shown inFig. 2, where it may be seen that on the side of the frame 2 oppositethe adjustable weight and dash pot mechanism, an arm 26a is mounted onand keyed to the shaft 29 so as to move with the arms 26. The arm 26a isprovided with an outwardly extending roller 33 which bears against thefree end of the lever 34 pivoted at 35. The

pivoting of the lever 34 is obtained by afiixing one end of the lever toan end of a small shaft '36 which extends through and is journaled inthe side walls of a box or container 31 rigidly secured to the frame 2in a suitable manner. On the interior of the container 31 the shaft 36carries a small arm 38 which, being fixed to the shaft, 'moves with thelever 34. The arm 38 bears against a plunger 40 which is reciprocablymounted in a primary hydraulic fluid brake cylinder 4| contained withinthe box 31. The end of the cylinder 4|, inwardly of the plunger, opensinto a pipe or conduit 42 which communicates with a header 43 from whichfluid pressure created by the plunger may be transmitted to one or moreof the tubes or lines 44, 45 and 46 connected through valves 41, 48 and49 respectively, to the header 43 (see Fig. 2).

As shown in Fig. 2, the flexible tube 45 may, by opening the valve 48,communicate with a secondary hydraulic fluid brake cylinder 50 which maybe bolted a spaced distance from the brake shoe 5. A plunger 5| isreciprocablymo'unted in the cylinder 5|! and its plunger rod bearsagainst the free'end of the long arm l5 of the bell crank lever l4.Thus, should the web become loose and allow the roller 25 to drop,causing the arms 26 to rotate from the full line position (Fig. 2) in aclockwise direction to their dotted line position, due to aninsuflicient tension in the web W1 which is being withdrawn at presentfrom the roll R1, the mechanical movement of the arms 26 will betransmitted through the levers 34 and 38 to the plunger 40, converted toan increased fluid pressure which is transmitted through conduit 42,header 43, and the tube 45 which communicates with the secondarycylinder 50, the side walls of which are afiixed to the brake shoe 5 ofthe brake located on the web roll R1. In thecylinder 50 the increasedfluid pressure will be converted by the plunger 5| to mechanical forcewhich will actuate the bell crank lever and tighten the brake shoes 4and 5 so that the web roll R1 will not unwind as swiftly and the amountof the Web W between the guide rolls 22 and 23 will decrease, therebydrawing the floating control roller 25 back up toward the full lineposition shown in Fig. 2 and increasing the tension in the web. It maybe readily seen that drawing the roller 25 upwardly will operate todecrease the braking effect on the web roll R1, and thereby compensatethe tension.

When the proper tension, determined largely by the adjustable weight,has been established, it will be automatically maintained by the controlmeans described above.

Should the withdrawal of the web W1from web roll R1 be stopped suddenly,or should slack occur in the web W1, the arms 26 will rotate relativelyquickly in a'clockwise direction (looking at Fig. 2) to the dotted lineposition shown therein and braking of the web roll R1 will be effected,thereby preventing overrunning of the web. 3

Apparatus embodying the present invention is very advantageous in thatit also provides a very flexible system of control of a plurality of webrolls. For example, it may be seen from Fig. 1 that the tension controlroller 25 associated with the web W1 may control not only the web rollR1 from which the web W1 is being withdrawn, but may also control theweb rolls R2 and R4. by transmittal of fluid pressure through the tubes44 and 46 respectively.

By having one tension control roller control the brake mechanism ofseveral web rolls, a single web may be fed in the same path successivelyfrom the several web rolls as they expire without changing the setup ofthe machine. If it is desired to feed one web to the printing machineand the amount of printingbeing done requires a length of web equivalentto between two and three web rolls, the web may be continuously suppliedfrom the apparatus shown in Fig. 1 by operation in the following manner.The web is withdrawn from the web roll R1 with the valve 48 open topermit the tension mechanism to control the web roll R1. As the web fromweb roll R1 is about to expire, the leading edge of web from web roll R2is afiixed thereto by what is commonly known in the art as a paster orsplice. As web begins to be withdrawn from web roll R2 the tensioncontrol thereof may be obtained by opening the valve 47 on line 44leading to the web roll R2 and closing valve 48 on line 45 leading tothe now expired r011 R1. By a similar pastel, web from the web roll R4may be connected to the web from web roll R2 as it expires and thecontinuous feeding of web from deck I may continue, such web, however,being withdrawn from web roll R4 situated in deck II. The tensioncontrol of the web withdrawn from web roll R4 is controlled by thecontrol roller 25 operating to control web roll R4 by communication offluid pressure through line 46 when the valve 49 is opened.

In deck II the tension control roller 225 associated with web W200 maycontrol not only Web withdrawn from web rolls R3 and R4 situated in deckII through lines 262 and 26! respectively, but also web withdrawn fromweb rolls R2 and Rethrough lines 260 and 263 respectively.

The web W300 in deck III may be withdrawn from web rolls R4, R5, R6 andR8 and the tension control roller 325 may control the web rollsmentioned through the lines 364, 366, 365 and 361 respectively.

Similarly, the web W400 in deck IV may be withdrawn from web rolls R0,R2 and R2 and the tension control roller 425 may control the web rollsmentioned through lines 468, 410 and 459 respectively.

Of course, it may be seen that the system shown in Fig. 1 is merelyillustrative and the tension control mechanism of any deck could bearranged so as to control as many web rolls as may be practicallydesirable. This invention may be applied to many types of printingmachines having one or more printing units into which a continuous webmay be fed and printed. Such printing machines may include rotarypresses of the unit as well as the multi-deck type, such as are used inthe printing of newspapers and the like.

As another example of the operation of the system shown .in Fig. I,assume that it be desired to feed two webs simultaneously from decks IIand III and a continuous web of between two and three web rolls inlength is required for the printing job. Fresh web rolls may be placedon all the web roll mounts during a period when the printing machine isshut down. Then the feeding of webs W200 and W300 simultaneously may bestarted. Web W200 may be successively drawn from web rolls R3, R4, andR2, all of which may be controlled by the control roller 225 associatedwith the web W200. Web W300 may bewithdrawn from web rolls R5, R6, andRs in succession, all of said rolls being controlled by the controlroller 325 associated with the web W300.

'It may be noted that when a plurality of webs are being withdrawnsimultaneously, and one of such webs breaks, the ,Web roll from which itis being withdrawn will be automatically stopped in a relatively shorttime. Such breakage will necessitate a stoppage of the printing machinewhich will automatically stop any of the remaining webs left running,because stopping the printing ,will allow the-occurrence of slack insuch webs, thereby permitting a movement of the control rollers which,as previously described, is transmitted to the braking means on the webrolls, preventing overrun of the web rolls. Further, if trouble shouldbegin at the printing machine, it is only necessary to stop the machineto prohibit feeding of the webs in a relatively quick time.

It is to be understood that variations and modifications of the specificdevices herein shown and described for purposes of illustration andexplanation, may be made without departing from the spirit of theinvention.

What I claim is:

1. Web supply apparatus for feeding one or more webs to a multiple-deckprinting machine which comprises a stationary frame for holding webrolls in decks corresponding to the decks of the printing machine, saidframe adapted to hold one or more web rolls in each deck, braking meansassociated with each of said web rolls, means for withdrawing a web fromeach of said decks simultaneously, tension-responsive control de-..

vices associated with the web of each deck between the web rolls thereofand the withdrawing means thereof, a primary hydraulic brake cylinderfor each deck, operable by the tension-responsive device thereof, asecondary hydraulic brake cylinder situated adjacent each web roll tooperate the braking means thereof, and means for selectively connectingthe primary brake cylinders of each deck to one or more of the secondarybrake cylinders, which need not be disposed in the same deck.

2. Web supply apparatus which comprises a plurality of web rolls,braking means for each of said web rolls, means for withdrawing websfrom said web rolls, a tension control mechanism associated with eachweb between the web rolls and the withdrawing means for maintainingsubstantially uniform web tension, a primary hydraulic fluid brakecylinder for each control mechanism operable by said control mechanism,a plurality of secondary fluid hydraulic brake cylinders each of whichis adapted to operate the braking means of one of said Web rolls, andmeans to selectively connect any of the primary cylinders to a pluralityof said secondary cylinders at the same time.

3. Web supply apparatus which comprises a plurality of web rollsarranged in decks for feeding web to a printing machine having aplurality of printing units, means for' withdrawing a web at each ofsaiddecks; braking means for each of said web rolls, a tension controlmechanism associated with each of the webs between the web rolls and thewithdrawing means formaintaining substantially uniform web tension, aprimary hydraulic fluid brake cylinder for each deck operable by thecontrol mechanism of said deck, a plurality of secondary hydraulic fluidbrake cylinders each of which is adapted to operate the braking means ofone of said web rolls, and means to selectively connect any of theprimary cylinders to one of a plurality of secondary cylinders, whichneed not be in the same deck.

4. Web supply apparatus which comprises a series of web rolls, a brakefor each of said rolls, a plurality of independent web withdrawingmeans, each adapted to withdraw the web from any one of said rolls, acontrolling member associated with each web withdrawing means, eachcontrolling member being movable in response to variations in webtension, and means for selectively connecting any one of saidcontrolling members to any one of said brakes to operate the brake soconnected in response to variations in web tension whereby the tensionof a web withdrawn from any roll by any of the web withdrawing means maybe automatically regulated by the control of the brake of the web rollfrom which the web is being withdrawn.

5. Web supply apparatus which comprises a series of web rolls arrangedin decks for feeding web to a printing machine having a plurality ofprinting units, means at each of said decks for withdrawing a web fromany roll of a plurality of decks, a brake for each of said web rolls, acontrolling member associated with each web withdrawing means, eachcontrolling member being movable in response to variations in webtension, and means for selectively connecting each of said controllingmembers to the brakes of any one of the rolls on a plurality of decks tooperate the brake so connected in response to variations in web tension,whereby the tension of the web withdrawn from any of a plurality ofrolls by any one of a plurality of web withdrawing means may beautomatically regulated by the control of the brake of the web roll fromwhich the web is being withdrawn.

' ROY A. STEWART.

